velox-bot/internal/events/welcome.go

package events

import (
	"context"
	"log"
	"strconv"
	"strings"

	"velox-bot/internal/db/services"

	"github.com/bwmarrin/discordgo"
)

// HandleGuildMemberAdd sends a configurable welcome message in a guild channel
// and an optional configurable DM to the joining user.
func HandleGuildMemberAdd(s *discordgo.Session, m *discordgo.GuildMemberAdd, svc *services.Services) {
	if s == nil || m == nil || svc == nil || svc.Welcome == nil {
		return
	}
	if m.User == nil {
		return
	}

	ctx := context.Background()
	guildID := mustParseInt64(m.GuildID)

	settings, err := svc.Welcome.GetSettings(ctx, guildID)
	if err != nil {
		log.Printf("welcome: failed to load settings for guild %s: %v", m.GuildID, err)
		return
	}
	hasWelcomeChannel := settings != nil && settings.ChannelID != 0

	memberMention := m.User.Mention()

	// Resolve guild/server name and user avatar for placeholders / visuals.
	guildName := ""
	userAvatarURL := ""
	if g, err := s.State.Guild(m.GuildID); err == nil && g != nil {
		guildName = g.Name
	} else if g, err := s.Guild(m.GuildID); err == nil && g != nil {
		guildName = g.Name
	}
	if m.User.Avatar != "" {
		userAvatarURL = discordgo.EndpointUserAvatar(m.User.ID, m.User.Avatar)
	}

	if hasWelcomeChannel {
		// Build guild welcome message.
		channelID := strconv.FormatInt(settings.ChannelID, 10)
		welcomeMsg := strings.TrimSpace(settings.WelcomeMessage)
		if welcomeMsg == "" {
			// Default message when none configured.
			// "<user>! Welcome to <server>! Have fun!"
			welcomeMsg = "<user>! Welcome to <server>! Have fun!"
		}
		welcomeMsg = strings.ReplaceAll(welcomeMsg, "{user}", memberMention)
		if guildName != "" {
			welcomeMsg = strings.ReplaceAll(welcomeMsg, "{server}", guildName)
			welcomeMsg = strings.ReplaceAll(welcomeMsg, "<server>", guildName)
		}
		welcomeMsg = strings.ReplaceAll(welcomeMsg, "<user>", memberMention)

		embed := &discordgo.MessageEmbed{
			Title:       "👋 Welcome!",
			Description: welcomeMsg,
			Color:       0xFFA500,
			Footer: &discordgo.MessageEmbedFooter{
				Text: "ID: " + m.User.ID,
			},
		}
		if userAvatarURL != "" {
			embed.Author = &discordgo.MessageEmbedAuthor{
				Name:    m.User.Username,
				IconURL: userAvatarURL,
			}
			embed.Thumbnail = &discordgo.MessageEmbedThumbnail{
				URL: userAvatarURL,
			}
		}
		gif := strings.TrimSpace(settings.WelcomeGIFURL)
		if gif == "" {
			// Default GIF when none configured.
			gif = "https://images-ext-1.discordapp.net/external/uJ6XfdK2WwDnei3RmNWUqSiOVboC4mK9r78TtgVE_9g/https/media.giphy.com/media/XD9o33QG9BoMis7iM4/giphy.gif"
		}
		embed.Image = &discordgo.MessageEmbedImage{URL: gif}

		if _, err := s.ChannelMessageSendComplex(channelID, &discordgo.MessageSend{
			Content: memberMention,
			Embed:   embed,
		}); err != nil {
			log.Printf("welcome: failed to send channel welcome in guild %s: %v", m.GuildID, err)
		}
	}

	// Optional DM.
	dmText := ""
	if settings != nil {
		dmText = strings.TrimSpace(settings.WelcomeDM)
	}
	if dmText == "" {
		// Default DM when none configured.
		// "Welcome to <server>! Have fun!"
		dmText = "Welcome to <server>! Have fun!"
	}
	dmText = strings.ReplaceAll(dmText, "{user}", memberMention)
	if guildName != "" {
		dmText = strings.ReplaceAll(dmText, "{server}", guildName)
		dmText = strings.ReplaceAll(dmText, "<server>", guildName)
	}

	dmCh, err := s.UserChannelCreate(m.User.ID)
	if err != nil {
		log.Printf("welcome: failed to create DM channel for user %s: %v", m.User.ID, err)
		return
	}
	if _, err := s.ChannelMessageSend(dmCh.ID, dmText); err != nil {
		log.Printf("welcome: failed to send DM welcome to user %s: %v", m.User.ID, err)
	}

	// Default role assignment.
	if svc.DefaultRole != nil {
		roleID, err := svc.DefaultRole.GetRole(ctx, guildID)
		if err != nil {
			log.Printf("defaultrole: failed to get default role for guild %s: %v", m.GuildID, err)
		} else if roleID != 0 {
			if err := s.GuildMemberRoleAdd(m.GuildID, m.User.ID, strconv.FormatInt(roleID, 10)); err != nil {
				log.Printf("defaultrole: failed to assign role %d to user %s in guild %s: %v", roleID, m.User.ID, m.GuildID, err)
			}
		}
	}
}